There is no apps in the store because Microsoft refuses to allow developers access to the private API.. Also I spoke with someone at ATT and they told me that you will not see this turned on for ANY ATT phones because it would prevent users from going over. So you can thank both Microsoft and ATT..
I plan on switching once Verizon finishes setting up their network here in Alaska. Once I found out the reason behind ATT actually blocking the "BUILT IN" data sense from working that was the last straw.
ALSO there was a company working on providing My Data Manage for windows phones but Microsoft is most likely going to refuse to allow them access to the private API unless they pony up serious cash. The fact that Microsoft is being real jerks about this when their phones and other windows 8 devices are selling like lead balloons just goes to show how incredibly stupid they have become. On the one hand they cry that not enough developers want to write software for windows 8, on the other they refuse to allow developers access to the apis! Stupid idiots..